Preparation of glucosamine by hydrolysis of chitosan with commercial α-amylase and glucoamylase

Objective  

In order to overcome the defects of chemical hydrolysis approach to prepare glucosamine, an enzymatic hydrolysis method was developed.     

Characterization of (68)Zn uptake, translocation, and accumulation into developing grains and young leaves of high Zn-density rice genotype

Zinc (Zn) is an essential micronutrient for humans, but Zn deficiency has become serious as equally as iron (Fe) and vitamin A deficiencies nowadays. Selection and breeding of high Zn-density crops is a suitable, cost-effective, and sustainable way to improve human health. However, the mechanism of high Zn density in rice grain is not fully understood, especially how Zn transports from soil to grains. Hydroponics experiments were carried out to compare Zn uptake and distribution in two different Zn-density rice genotypes using stable isotope technique. At seedling stage, IR68144 showed higher ⁶⁸Zn uptake and transport rate to the shoot for the short-term, but no significant difference was observed in both genotypes for the long-term. Zn in xylem sap of IR68144 was consistently higher, and IR68144 exhibited higher Zn absorption ratio than IR64 at sufficient (2.0 μmol/L) or surplus (8.0 μmol/L) Zn supply level. IR64 and IR68144 showed similar patterns of ⁶⁸Zn accumulation in new leaves at seedling stage and in developing grains at ripening stage, whereas ⁶⁸Zn in new leaves and grains of IR68144 was consistently higher. These results suggested that a rapid root-to-shoot translocation and enhanced xylem loading capacity may be the crucial processes for high Zn density in rice grains.     

区域内校际间高考成绩评价的探索与实践——以深圳部分学校2010年高考成绩为例

由于学校之间生源质量和考生规模等方面的客观差异,以升学率或者考上清华、北大的人数评判学校的高考成绩是不科学和不公平的。要在不同的学校之间进行高考成绩的比较或评价,较为科学和公平的思路与方法是将高考结果与其高一生源质量进行比较,着重从学校的“教育教学培养提升能力”来评价,主要的分析和评价指标有百分位变化指数、目标达成度、同名次段人数保持率、相近质量生源考生上线率和平均分等。     

从语域理论看医学英语语篇的翻译

近年来,语域理论已被越来越多地引入到翻译研究当中。文章分析了医学英语语篇中的语域特征,从语场、语旨和语式三个层面探讨语域理论对翻译实践和评论的指导作用。     

Distributed Time Synchronization in Wireless Sensor Networks via Second-Order Consensus Algorithms

This paper proposes a distributed second-order consensus time synchronization, which incorporates the second-order consensus algorithm into wireless sensor networks. Since local clocks may have different skews and offsets, the algorithm is designed to include offset compensation and skew compensation. The local clocks are not directly modified, thus the virtual clocks are built according to the local clocks via the compensation parameters. Each node achieves a virtual consensus clock by periodically updated compensation parameters. Finally, the effectiveness of the proposed algorithm is verified through a number of simulations in a mesh network. It is proved that the proposed algorithm has the advantage of being distributed, asymptotic convergence, and robust to new node joining.     

以人为本的区域教育信息化促进校际公平应用策略研究

为了更加有效地利用教育信息化促进基础教育均衡发展、实现教育公平,需要深入研究不公平现象,丰富利用信息技术改善公平的应用策略。该文开展基于教师视角的校际不公平现象表现维度研究,发现校际间的不公平主要表现在资源不公平、机会不公平和管理不公平三个维度。同时,该文对当前教育信息化促进校际公平的相关策略进行了分析,发现目前的策略设计存在着功利主义、效率至上等倾向。以此为基础,该文提出教育行政管理部门应该以"以人为本"作为策略设计原则,利用信息技术,通过采用提供适切的资源、建立合作的机制、培育参与的文化等应用策略,促进区域内校际间公平的改善。     

Saber仿真技术在电力电子教学中的应用

将Saber仿真技术应用于电力电子技术课程的教学中,通过同步整流反激变换器实例,介绍了利用Saber软件建模、进行参数设计及仿真分析的过程。仿真实验得到的触发脉冲、输出电流和输出电压结果与同步整流管驱动电路的原理分析一致。应用Saber软件可使电力电子技术的原理与概念形象化,将原理性内容更直观的展示出来,学生对其理解程度也会更加深入。     

医院环境下的电磁污染实验分析

以医院环境为背景,在相关电磁辐射实验的基础上,论述了电磁污染的具体危害及对医疗仪器和就医患者的影响,并提出了防治措施。基于有限元法(FEM),并结合电磁理论,初步形成了在复杂电磁环境下的EMC系统仿真。通过实验结果和理论分析的结合,揭示了医院环境电磁污染防治的必要性。     

农村社会转型中城郊社区公共服务的困境及其对策——基于瑞安市W社区的调查

温州"三分三改"工作为城郊社区的撤村建社准备了必要的制度基础,城中村如何融合成社区是一项非常有意义的研究工作。本文通过对瑞安市W社区的详尽调查,分析村郊社区向城市社区转变过程中存在的公共服务缺口,并对如何有效改进城郊社区公共服务提出对策建议。     

高校毕业生离校教育模式新探索

近年来,毕业生离校教育备受关注。毕业生离校教育工作是大学生思想政治教育工作的重要组成部分,也是毕业生离校前的最后一项工作,不仅事关学校的安全与稳定,而且关系毕业生成长成才问题。我们在相关调研基础之上对毕业生离校教育经验进行了总结研究,并在实践中不断探索离校大学生思政教育新方式,形成了"五个点"毕业生离校教育举措,即离校前的就业创业教育、理想信念教育、诚信感恩教育、遵纪守法教育、情感教育等,倡导毕业生文明、安全、满意离校,为当代大学生成长、成才、成功奠定良好的基础。